Knitting method and apparatus



Aug. 6, 1946. B. NYHUIS KNITTING METHOD AND APPARATUS Filed Sept. 16, 1944 INVENTOIf.

fierZ/Yy/uua, BY I g y Patented Aug. 6, 1946 KNITTING METHOD AND APPARATUS Bert Nyhuis, Kankakee, Ill., assignor to Bear Brand Hosiery (10., Chicago, 111., a corporation of Illinois Application September 16, 1944, Serial No. 55 1, 198

7 9 Claims.

This invention relates to improvements in circular knitting machines and methods of knitting and its purpose is to provide improved means for controlling the operation of such a machine by the application of air under pressure at the place where the stitches are formed. The invention may be employed with particular advantage in the operation of-a circular knitting machine for producing seamless nylon hosiery having a double welt portion around the top.

In the operation of a circular knitting machine to make the welt portion of a stocking, the machine starts on alternate needles four courses of fabric and this fabric is then taken off of the needles. and held by transfer jacks while the needles continue their operation in the knitting of the remainder of the fabric. When the knitting of the welt fabric has been completed, the needles are operated to remove the initial stitches from the transfer jacks and then to knit a seam which completes the formation of the tubular top portion or welt.

The use of such a knitting machine in forming the welt fabric has given rise todifficulty when nylon yarn is employed because of the tendency of the knitted fabric to bunch up and form a tangled mass as the knitting proceeds, with the result that distorted stitches and wrinkles are present in the welt portion of the completed stocking, thereby giving it an unattractive appearance. This problem has been solved, to some extent, by the controlling method disclosed in the United istates patent to R. C. Williams, No..2,275,276, dated March 3, 1942 according to which a jet of air under plfissure is directed against the fabric as it is being formed, so that the fabric is projected inwardly within the needle cylinder and held in an extended condition opposite the jet. This arrangement has not proved to be entirely satisfactory, however, because the portion of the fabric which is extended by the jet tends to rub against the downwardly looped fabn'c at the opposite side of the needle cylinder, thereby causing the suspended fabric to twist upon itself and give rise to unsightly wrinkles and surface formations which are only less objectionable than those produced in the operation of machines not equipped with the controlling device of said patent. I

These difliculties have been overcome by the present invention through the provision of improved apparatus in which a jet of air under pressure, introduced in the knitting area between the needle cylinder and the hook carrying dial, is caused to carry the loop of knitted fabric against a depending annular baflle or shield which extends downwardly from the rotary dial,

so that the fabric which is extended by the air jet to keep its opposite layers apart is held by the intervening baffle from engagement with the suspended loop or double layer of fabric at the opposite side of the cylinder. This bafile, by virtue. of its shape and its position with respect to the air'jet, serves to direct the air downwardly into the pocket of fabric as it is formed so that this direction of the air current is a major factor in preventing the distortion and formation of wrinkles which attend the making of the fabric where such air directing means is not used. By this method, the double welt fabric is progressively formed while maintaining the opposite walls apart at the place of knitting and preventing the opposed parts of the inner wall of the Welt from engaging each other at any time during the knitting operation. These and other objects and advantages of the present invention will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawing in which one embodiment of the invention is illustrated. In the drawing, the single figure shows a vertical axial section through the principal portions of the upper part of a circular knitting machine embodying the features of the present invention.

As illustrated in the drawing, the invention is embodied in a circular knitting machine comprising a needle cylinder l l! which is suitably supported for rotary movement about its vertical axis and which is rotated or oscillated as required in the making of seamless stockings by suitable actuating mechanism not shown. Secured to the needle cylinder I!) is a sinker,ring ll carrying the web holders or sinkers l; which coact individually with the annular series of needles l3 carried by the cylinder [9 during the knitting operation. The web holders I2 are slidably mounted for radial movement and are actuated by a cam groove li formed in an annular cap member 14 which rests upon the sinker ring H and carries adjustable stop screws adapted to engage a stationary post, not shown, for limiting its angular motion in either direction. The yarn feeding mechanism and other usual parts associated with the needles and the web holders are not illustrated since they do not in themselves constitute parts of the present invention.

The latch guard ring it of the machine carries an inwardly extending bracket [6 provided at its inner end with a hub portion H in which is journaled, in axial alignment with the needle cylinder [0, a shaft having secured to the lower end thereof a circular dial I! having radial guideways, in which are mounted the loop holding hook members or transfer jacks l8 which cooperate with alternate knitting needles l3 during the formation of an initial or set-up course for the stocking welt and also during the formation of the seam which finally closes the welt. The dial I! is rotated in unison with the needle cylinder l9 by suitable driving connections including a shaft 19 having fixed thereon a bevel pinion 2!) arranged 3 to mesh with a bevel gear 2| fixed upon th upper end of the shaft which carries the dial. Atjcertain times during the rotation, theloop holding hooks l8 are actuated by retractable cams, not illustrated, carried by a cam plate 22 which is mounted in fixed position, and in coaxial relationship to the dial 11, upon the bracket l6. The needles l3 are actuated by suitable cams at proper times during the rotation of the needle cylinder as is usual in machines of this type.

At a point outwardly fromand somewhat above adapted to impinge upon the outer annular surface 27 of a circular baffle or shield 2! which is secured to the under Side of the dial H in concentric relationship thereto. The surface 21 tapers downwardly and unites with a'cylindrical surface 27* which extends around the lower end of the balile. V. I V

In the operation of the machine, after the initial courses of thewelt fabric 30 have been formed by the knitting needles, theweb holding hooks is are operated to take the fabric off of the needles and to hold the upper'edge thereof as shown in the drawing; As the knitting operation continues', the length of the annular piece of fabric increases and itforms a progressively increasing double walled loop extending downwardly between the baffle 2-1 and the cylinder lil. During this knitting operation the air jet from the nozzle carries the inner wall or layer of the fabric against the surface 2'! and the surface 21 of the baffle so that the inner and-outer walls of the welt are kept apart in the region of the knitting'station. The air jet is deflected downwardly from the surface 27* and thus tends to hold the 'double'walled welt in concentric relationship to the cylinder it] as its length increases and, in

addition, the presence of the baffle within the welt fabric prevents the opposite portions of the inner annular welt from contacting each other as the dial rotates and the length of the welt increases. The objectionable twisting of the suspended welt fabric upon itself is thus overcome. This effect may be increased or regulated by varying the taper of the surface 21 and by varying the length 1 of the cylindrical surface 21'. The action of the air jet serves to maintain the welt extended and the stitches under tension in the stitching region so that a uniform product is obtained' Many of the advantages of the present invention may be obtained by using the bafiie alone, without any air current, in which case this member serves merely as a shield to separate the opposed portions of the inner wal lof fabric. When the length of the welt fabric has increased to the desired extent, the upper edge of the fabric is removed from the hooks l8 and united with the outer portion of the fabric to form the completed welt.

One form of the invention has been shown and l described by way of illustration, but 'it'will be understood that it may be constructed in vari 1. The method of controlling the formation of the stitches in a fabric knitted by a circular knitting machine which consists in holding the fabric by air under pressure against a baffle located on the inside of the circular fabric.

2. The method of controlling the formation of the stitches in a fabric knitted by a circular knitting machine which consists in directing air under pressure against the fabric as it is being formed and deflecting the air current to hold opposed parts of the fabric out of contact with each other.

3. The method of controlling the formation of the stitches in a tubular fabric knitted on a circular knitting machine which consists in directing. a current of air under pressure against the fabric as it is being formed and causing said current to move axially of the tubular fabric to hold opposed portions thereof out of contact with each other.

4. In a circular knitting machine having an annular series of needles for knitting a tubular fabric, the combination of means for directing a current of air under pressure against said fabric as it is being formed to hold said fabric extended, and supporting means located on the inside of the annular fabric against which said fabric is forced by said air current.

5. In a circular knitting machine having an annular series of needles for knitting a tubular fabric, the combination of means for directing a current of air under pressure against said fabric as it is being formed to hold said fabric extended, and a baflie mounted behind said fabric and adapted to deflect said air current axially of the tubular fabric.

6. In a circular knitting machine having an annular series of needles for knitting a tubular fabric, the combination of means for directing a current of air under pressure against said fabric as it is being formed to hold said fabric extended, and a baffle against which said fabric is forced by said air current, said bailie having an inclined surface arranged to deflect said air current axially of the tubular fabric.

7. Ina circular knitting machine having an annular series of needles for knitting a tubular fabric, the combination of meansfor directing a current of air under pressure against said fabric as it is being formed to hold said fabric extended, and an annular bafiie positioned to be within the forming tubular fabric with a part thereof located in the path of travel of said a r current.

8. In a circular knitting machine having an annular series of needles for knitting a tubular fabric, the combination of means for directing a current of air under pressure against said fabno as it is being formed to hold said fabric extended, and a bafiie positioned to be within the forming fabric and having a downwardly converging annular surface against which said fabric is forced by said air currrent.

9. In a' circular knitting machine having an annular series of needles for knitting a tubular fabric, the combination of means for directing a current of air under pressure against said fabric as it is being formed to hold said fabric extended, -ab'afiie positioned to be within the forming fabric and having a downwardly converging annular surface against which said fabric is forced by. said air current, said baflie also having a cylindrical surface extending downwardly from said first named surface. BERT NY I-IUIS. 

